ios内存限制
不同内存的苹果机型上(1G,2G,3G,4G…)，游戏内存的峰值一般最高多少能保证不闪退？
一般来讲最保险的就是不超过机器总内存的50%，具体每个机型的内存限制在列出在下面。
原贴：《ios app maximum memory budget》
注意事项：查看当前app占用多少内存，通过OS的API来获取，而不要通过引擎自己的API来获取。
IOS内存不足闪退的表现：《 iOS内存分析下-前台内存耗尽闪退(FOOM)》
device: (crash amount/total amount/percentage of total)
iPad1: 127MB/256MB/49%
iPad2: 275MB/512MB/53%
iPad3: 645MB/1024MB/62%
iPad4: 585MB/1024MB/57% (iOS 8.1)
iPad Mini 1st Generation: 297MB/512MB/58%
iPad Mini retina: 696MB/1024MB/68% (iOS 7.1)
iPad Air: 697MB/1024MB/68%
iPad Air 2: 1383MB/2048MB/68% (iOS 10.2.1)
iPad Pro 9.7": 1395MB/1971MB/71% (iOS 10.0.2 (14A456))
iPad Pro 10.5”: 3057/4000/76% (iOS 11 beta4)
iPad Pro 12.9” (2015): 3058/3999/76% (iOS 11.2.1)
iPad Pro 12.9” (2017): 3057/3974/77% (iOS 11 beta4)
iPad Pro 11.0” (2018): 2858/3769/76% (iOS 12.1)
iPad Pro 12.9” (2018, 1TB): 4598/5650/81% (iOS 12.1)
iPad 10.2: 1844/2998/62% (iOS 13.2.3)
iPod touch 4th gen: 130MB/256MB/51% (iOS 6.1.1)
iPod touch 5th gen: 286MB/512MB/56% (iOS 7.0)
iPhone4: 325MB/512MB/63%
iPhone4s: 286MB/512MB/56%
iPhone5: 645MB/1024MB/62%
iPhone5s: 646MB/1024MB/63%
iPhone6: 645MB/1024MB/62% (iOS 8.x)
iPhone6+: 645MB/1024MB/62% (iOS 8.x)
iPhone6s: 1396MB/2048MB/68% (iOS 9.2)
iPhone6s+: 1392MB/2048MB/68% (iOS 10.2.1)
iPhoneSE: 1395MB/2048MB/69% (iOS 9.3)
iPhone7: 1395/2048MB/68% (iOS 10.2)
iPhone7+: 2040MB/3072MB/66% (iOS 10.2.1)
iPhone8: 1364/1990MB/70% (iOS 12.1)
iPhone X: 1392/2785/50% (iOS 11.2.1)
iPhone XS: 2040/3754/54% (iOS 12.1)
iPhone XS Max: 2039/3735/55% (iOS 12.1)
iPhone XR: 1792/2813/63% (iOS 12.1)
iPhone 11: 2068/3844/54% (iOS 13.1.3)
iPhone 11 Pro Max: 2067/3740/55% (iOS 13.2.3)
device RAM: percent range to crash
256MB: 49% - 51%
512MB: 53% - 63%
1024MB: 57% - 68%
2048MB: 68% - 69%
3072MB: 63% - 66%
4096MB: 77%
6144MB: 81%
Special cases:
iPhone X (3072MB): 50%
iPhone XS/XS Max (4096MB): 55%
iPhone XR (3072MB): 63%
iPhone 11/11 Pro Max (4096MB): 54% - 55%